Current research results indicate that mutation of genes in the autophagy pathway, including ATG16L1, NOD2, LRRK2 (leucine-rich repeat kinase 2), IRGM, ULK1 (Unc-51-like autophagy-activating kinase 1), increases the risk of developing severe fibrous CD [57]. This evidence concerns the gene ULK1 and Cowden disease.